Ordinarily center pivot irrigation systems continue to operate even during a severe rainstorm. The result is a waste of energy, water, and excess erosion. To avoid such waste it is necessary that one travel to the site of the system when heavy rainfall is occurring. Not only is such travel costly, its need generally occurs at inopportune times. Since such systems are typically located one to ten miles distant, there is an inherent time-lag, with ensuing extra costs.
Shut off controls responsive to telephone or radio signals have been used to obviate such travel. However, such control systems are expensive, often costing in the thousands of dollars. Also, it is not unusual for rainfall quantities to vary widely, as much as one to two inches within a range of one to five miles. The result is that such remote controls are used when they should not be or not used when they should be.